Dielectric waveguide filter with inductive windows and coplanar line coupling

Abstract

A dielectric waveguide tube band-pass filter assuming lower characteristic change upon mounting, and having smaller dimensions and lower loss. Conductor layers ( 2 a , 2 c ) are formed on the top and bottom surfaces of a dielectric substrate ( 1 ), wherein the top conductor layer 2 a and the bottom conductor layer 2 c are connected together through via-holes ( 3 a ). The via-holes ( 3 a ) are formed in at least two rows along the signal transfer direction. In the dielectric waveguide tube configured by the top and bottom conductor layers ( 2 a , 2 c ) and the via-holes ( 3 a ), via-holes ( 3 b ) are arranged in the signal transfer direction at spacing equal to or below ½ of the in-tube wavelength to thereby configure resonators. The dielectric band-pass filter is configured by coupling adjacent resonators together through the via-holes ( 3 b ) configuring inductive windows. On the surface of the dielectric substrate ( 1 ), a co-planar line ( 4 ) including the conductor layer ( 2 ) as the ground and the conductor layer (2 b ) as a signal conductor is configured so as to overstride the inductive windows configured by the via-holes ( 3 a ).

1. A filter comprising a dielectric waveguide tube structure including a top conductor layer and a bottom conductor layer on surfaces of a dielectric substrate,
 wherein a side wall of the dielectric waveguide tube and inductive windows are configured by conductors connecting said top conductor layer and said bottom conductor layer together; 
 a planar line is configured on the surface of at least one of said top conductor layer and said bottom conductor layer; and 
 wherein said planar line comprises a slot and conductors on both sides of said slot are connected together via a conductor piece for adjusting said filter. 
 
   
   
     2. The filter according to  claim 1 , where said planar line is a coplanar line for inputting or outputting a signal and said filter further comprises a conversion structure for the waveguide tube. 
   
   
     3. The filter according to  claim 1 , wherein said planar line further comprises a second slot disposed along a signal transfer direction in the waveguide tube so as to configure a co-planar line;
 wherein a signal conductor is formed between said slots and said conductor piece connects ground conductors disposed on both sides of said signal conductor. 
 
   
   
     4. The filter according to  claim 3 , wherein the coplanar line inputs or outputs a signal, and said filter further comprises a conversion structure for the waveguide tube. 
   
   
     5. The filter according to  claim 3 , wherein said conductor piece is disposed on a flip-chip mounting board and bumps. 
   
   
     6. The filter according to  claim 1  wherein:
 said conductors connecting said top conductor layer and said bottom conductor layer comprise via holes; 
 said via holes are disposed in at least a first via hole array and a second via-hole array; 
 said via-holes in said first via hole array and said second via hole array are arranged in a signal transfer direction at spacing equal to or below ½ of an in-tube wavelength in a desired band; and wherein 
 said inductive windows are configured by said second via hole arrays and couple together resonators in said waveguide tube; said resonators being configured by an area surrounded by said first and second via-hole arrays, said top conductor layer and said bottom conductor layer. 
 
   
   
     7. A filter comprising a dielectric waveguide tube structure including a top conductor layer and a bottom conductor layer on surfaces of a dielectric substrate,
 wherein a side wall of the dielectric waveguide tube and inductive windows are configured by conductors connecting said top conductor layer and said bottom conductor layer together; 
 a planar line is configured on the surface of at least one of said top conductor layer and said bottom conductor layer; 
 said planar line disposed on said dielectric substrate is a co-planar line configured by two slots disposed along a signal transfer direction in the waveguide tube; 
 at least one of the opposite ends of said co-planar line is an open end, and a first conductor piece is disposed apart from said open end of a signal conductor; and 
 said first conductor piece and said signal conductor are connected together via a second conductor piece for adjusting said filter. 
 
   
   
     8. The filter according to  claim 7 , wherein said filter includes a coplanar line for inputting/outputting a signal, and a conversion structure for the waveguide tube. 
   
   
     9. The filter according to  claim 7 , wherein ground conductors disposed on both sides of said planar line are connected together via a third conductor piece disposed on a flip-chip mounting board and bumps. 
   
   
     10. The filter according to  claim 7 , wherein ground conductors on both sides of said signal conductor configuring said coplanar line are connected together via a third conductor piece. 
   
   
     11. A filter comprising:
 a dielectric waveguide tube structure including a top conductor layer and a bottom conductor layer on surfaces of a dielectric substrate; and 
 a conversion section formed on one of the surfaces of the dielectric substrate; 
 wherein a side wall of the dielectric waveguide tube and inductive windows are configured by conductors connecting said top conductor layer and said bottom conductor layer together; 
 wherein a coplanar line is configured on the surface of at least one of said top conductor layer and said bottom conductor layer, the coplanar line is disposed so as to overstride at least one of said inductive windows, and the coplanar line configures a subordinate transmission path; and 
 wherein the coplanar line is a signal input/output line directly connected to the conversion section so that the coplanar line is coupled with the waveguide tube and adjusts the coupling factor of the filter. 
 
   
   
     12. The filter according to  claim 11 , wherein ground conductors on both sides of a signal conductor configuring said coplanar line are connected together via a conductor piece. 
   
   
     13. The filter according to  claim 12 , wherein the conductor piece is disposed on a flip-chip mounting board and bumps. 
   
   
     14. A filter comprising:
 a dielectric waveguide tube structure including a top conductor layer and a bottom conductor layer on surfaces of a dielectric substrate; and 
 a conversion section formed on one of the surfaces of the dielectric substrate, 
 wherein a side wall of the dielectric waveguide tube and inductive windows are configured by conductors connecting said top conductor layer and said bottom conductor layer together; 
 wherein a first coplanar line is configured on the surface of at least one of said top conductor layer and said bottom conductor layer, the first coplanar line is disposed so as to overstride at least one of said inductive windows, and the first coplanar line configures a subordinate transmission path; 
 wherein a second coplanar line is configured on the surface of one of said top conductor layer and said bottom conductor layer for inputting or outputting a signal; and 
 wherein the first coplanar line is directly connected to the conversion section so that the first coplanar line is coupled with the second coplanar line.